1. Field of the Invention
The invention is based on a magnetic.
2. Description of the Prior Art
A conventional magnetic valve, particularly for a hydraulic unit, which is used for instance in an anti-lock brake system (OBOIST) or traction control system (TCS) or an electronic stability program system (ESP system), is shown in FIG. 1. As can be seen from FIG. 1, the conventional magnetic valve 110 includes a magnet assembly 5 for generating a magnetic flux 5.1, which magnet assembly in turn includes a housing 5.2, a coil winding 5.3, a coil body 5.4, and a covering disk 5.5; and a valve cartridge, which includes a capsule 60, a valve insert 10, a tappet 20, a restoring spring 30, and an armature 7. In the production of the magnetic valve 110, the capsule 60 and the valve insert 10 of the valve cartridge are joined together by pressing, and the valve cartridge is hydraulically sealed off from the atmosphere by a sealing weld 8. In addition, the valve insert 10 absorbs the pressure forces that occur in the hydraulic system and carries them onward to a fluid block, via a wedging flange 10.1 in a wedging region, not shown. In addition, the valve insert 10 conducts the magnetic flux 5.1, introduced by the joined magnet assembly 5, axially in the direction of the armature 7 via an air gap 11. The valve insert 10 furthermore receives the so-called valve body 40, which includes a sealing seat 41 into which the tappet 20 dips in sealing fashion in order achieve the sealing function of the magnetic valve 110. As can also be seen from FIG. 1, the tappet 20 and the restoring spring 30 are guided in the valve insert 10. The attachment of the magnet assembly 5 at the bottom is accomplished by pressing the covering disk 5.5 directly onto the magnetically conductive valve insert 10 of the valve cartridge. The capsule 60, likewise pressed onto the valve insert 10 and welded, has a lower region which is thrust in overlapping fashion onto the valve insert 10.
To adapt the conventional magnetic valve 110, functions are as a rule established; that is, a calibration is performed, in order as much as possible to minimize and compensate for variations in such properties of the parts as their geometry, magnetic properties, and so forth. For doing so, usually components that are easily accessible from outside are displaced counter to one another in accordance with an adjustment instruction, for instance to produce an equilibrium between contrary forces, until in a final position the desired function is assured. For the adaptation, the moving components should be readily accessible, which can limit further development of the integration of the parts in optimizing valve assemblies. Hence the conventional magnetic valve 110, before a lower valve part 12 is installed, is calibrated with simultaneous subjection of it to pressure and introduction of magnetic force. The adjustment of the magnetic flux 5.1 and thus of the magnetic force is done by increasing or decreasing the size of the air gap 11 by axial displacement of the valve body 40.
In German Patent Application DE 102005044672.8, not published before the priority date of the present application, of the same Applicant, a magnetic valve is described which distributes the described functions of the valve insert over a plurality of components, so that the valve insert can be designed more simply. In the described magnetic valve, the overlapping region of the capsule is lengthened in the direction of the wedging region and is wedged with a valve bush in the wedging region with the fluid block. Moreover, as the lower part of the valve cartridge, a sleeve is fitted with a sealing seat into the lengthened capsule. Because of the lengthening of the capsule into the fluid block, the sealing from the atmosphere and the wedging with the fluid block are advantageously accomplished via the valve bush, and no longer via the valve insert. As a result, the valve insert is relieved and can be designed more simply. Furthermore, one production step, for sealingly welding the capsule to the valve insert, can be dispensed with. Because the components are fitted into one another in sleevelike fashion, however, calibrating the magnetic valve is difficult to do.